A fixing device for thermally fixing a developer image on a recording sheet such as a paper sheet is disclosed, and the fixing device includes an endless belt, a nip member that comes into sliding contact with the inner circumferential surface of the endless belt, a pressure roller that forms a nip between the endless belt and the pressure roller, and a guide member that is disposed downstream from the nip in the rotational direction of the endless belt and guides the endless belt getting out of the nip between the nip member and the pressure roller.
In the fixing device, the guide member includes a downstream guide that guides the endless belt and a depressed portion that is formed between the nip and the downstream guide, and a gap is formed between the endless belt and the guide member by the depressed portion. Accordingly, it is possible to suppress heat of the endless belt from being lost to the guide member or to reduce sliding resistance between the endless belt and the guide member.